We've had good luck with DynamoDB, but it could be that it just fits our use case very well. What sort of frustration were you running into? (Honestly interested to avoid trouble down the line)
Most recently: hot hash key. DynamoDB uses the object to be persisted's hash key to route it to the right data cluster.
We're a SaaS company with lots of tiny customers and a few very large customers. We need to keep an index to show a specific customer only their data. That means the index for our largest customers gets hit a lot. The problem with this structure is we have to pay as if all of our customers were as popular as our biggest customers, or we get throttled. And even though the DynamoDB interface shows that you have provisioned 10x above your current usage, you still get throttled, because you're being throttled only in a single cluster.
So, let's say you solve that problem, but now you need to drop the troublesome index on a billion+ row table. With DynamoDB you can't change a table's indexes, so you have to migrate your table to a new table. Doing that without downtime is an incredible challenge.
Which reminds me of when they announced indexes. We were so excited only to find out we couldn't add indexes to our tables, but instead had to recreate them all.
The whole point of SaaS is to make our lives easier, but with DynamoDB our lives were much more difficult than just using Mongo.
Anyway, I need to do a blog post on this -- it's a bit too complicated for a HN comment. :-)
Yeah, I think all nosql db's will have that issue if you have extremely unbalanced sharding. This is an application level fault and should be solved there.
But, the thing that is extra bad about dynamo db is how they are paying for 10x higher provisioning as a stop gap, and still getting throttled. That sucks.
We're a SaaS company with lots of tiny customers and a few very large customers. We need to keep an index to show a specific customer only their data. That means the index for our largest customers gets hit a lot. The problem with this structure is we have to pay as if all of our customers were as popular as our biggest customers, or we get throttled. And even though the DynamoDB interface shows that you have provisioned 10x above your current usage, you still get throttled, because you're being throttled only in a single cluster.
So, let's say you solve that problem, but now you need to drop the troublesome index on a billion+ row table. With DynamoDB you can't change a table's indexes, so you have to migrate your table to a new table. Doing that without downtime is an incredible challenge.
Which reminds me of when they announced indexes. We were so excited only to find out we couldn't add indexes to our tables, but instead had to recreate them all.
The whole point of SaaS is to make our lives easier, but with DynamoDB our lives were much more difficult than just using Mongo.
Anyway, I need to do a blog post on this -- it's a bit too complicated for a HN comment. :-)